Lambis truncata, common name the giant spider conch, is a species of sea snail, a marine gastropod mollusc in the family Strombidae, the true conchs.

Lambis truncata is the largest and heaviest of spider shells, up to 40 cm.

[1] Younger shells are creamy white; columella and lip usually mauve brown when older.

[1] The distribution of Lambis truncata includes the Indian Ocean off [1] Aldabra, Chagos, Madagascar, Mauritius, Tanzania; the Bay of Bengal and in the Pacific Ocean along the Philippines.

Lambis truncata lives on rubble and coarse sand in shallow water.